Packs of small chunky 18mm thick blocks 
 
Your options for these are 
Pack of 3 : 8cm x 8cm 
Pack of 3 : 8cm x 6cm 
Pack of 6 : (3 of each of the above sizes) 

If you would like another size option (The thickness must still be 18mm) then please get in touch via Facebook or the website contact form, and I will add this option to the listing for you